As we get set for a significant thaw this weekend it shouldn't come as a surprise. Once again it coincides with what the MJO is showing...that we're headed into a 2-3 week period of mild weather. Make no mistake about it, the MJO is adamant the tour is underway through the warm phases of 4, 5, 6, and 7 between now and early February. Today's EURO forecasts this for the period January 17-31 (follow the dotted green line).
Notice the temperature anomalies each phase correlates to. Strongly warm! This next 2-3 weeks should also be wetter than normal.
Additionally the operational EPO on the EURO is shown positive compared to the base state.
As you can see below a positive EPO in January correlates to above normal readings in the Midwest and eastern U.S. During our recent cold snap the EPO was strongly negative so this is a significant reversal in a key teleconnection.
Here's the temperature departure on the EURO EPS ensembles for the rest of January.
Days 0-5. (ending January 22nd)
Days 5-10. (ending January 27th)
Days 10-15. (ending February 1)
The climate prediction center has this for temperatures in the 8-14 day outlook.
The 8-14 day precipitation departures are wetter than we've seen in about 3 months.
That leads me into the weekend storm which is now well forecast by the models. As I indicated yesterday the trends were for a westward track and a warmer solution around my area. I anticipated even more of a shift today and that has happened. Here's where the storm is projected to be Sunday evening, just north of Des Moines.
My entire area is in the warm sector so the majority of the precipitation from this event will come down as rain beginning Sunday. The dry slot with the latest track is more of a factor in my area and precipitation totals have come down today by more than 1/2". Even so amounts are significant for January but substantially less than yesterday around here. Here's what the GFS shows.
A larger perspective. You can clearly see the dry slot catching eastern Iowa and western Illinois.
The storm is a wet one as you can see with water vapor of more than an inch all the way to good old Cedar Rapids Sunday evening.
These amounts are more than 4 standard deviations above normal. Impressive!
While instability is marginal the dynamics will make up for what little CAPE there is. As temperatures head for the 50s Sunday evening in parts of the Midwest there is likely to be some thunderstorms. What CAPE there is shows up Sunday evening nosing into Iowa.
Last but not least the wintry side of the storm is going to be impressive. A shut down blizzard is likely from eastern South Dakota through central Minnesota and NW Wisconsin. The GFS is putting a real focus on that area.
Aside from some snow showers or flurries on the tail end of the storm, my area will escape with little in the way of wintry weather. In fact, before cold air returns late Monday highs may reach the 50s all the way to my southern counties. The GFS shows this for highs late Sunday night.
Hard to believe we can go from wind chills of 30 below to rain and thunderstorms in just a few days. In fact, if we get the 50s it will feel more than 80 degrees warmer than earlier in the week! Man, I just love that stuff. Roll weather...TS